In the offshore production fields, the flow lines which carry the production from the well to the platform, due toe characteristics of the crude oil and the low temperatures prevailing at the site where same are installed, usually at large depths where the water temperature can reach around 5.degree. C. are subject to severe obstruction problems, due to residues which are found dissolved in that oil--paraffins, asphaltenes, resins, wax, silica, etc.
It has been verified that those residues tend to accumulate in the line, although their formation may have occurred in a rather previous site. Depending upon the fluid flow rate, those residues do not deposit immediately as the water temperature lowers. It is known that fluid flow can occur at temperatures below the so-called pour point, that is, the lowest temperature at which a fluid flow due to its own weight (Standard ASTM-D97). This mean that, if pressure is applied to a fluid at a temperature below its pour point, it will flow.
In practice, however, the application of pressure in the pipelines comes up against severe limitations as regard equipment horsepower and dimensions. As the pipelines become longer, the problem of obstruction grows worse, and may reach some kilometers of extension.